from CSI.ca:
https://www.csi.ca/student/en_ca/student/exams/exams.xhtml#tabview=tab1
How to book an International and Caribbean Exam
Log into your student profile by using your Student Login ID and your Password and follow these instructions:
    Select “Book Exam” for the course exam you wish to write
    Select “Book Exam” again for the course exam you wish to write – a message will appear asking you to verify that you have checked for any course updates before proceeding. If yes then proceed by selecting “OK”
    If your course exam is offered as a computer base exam you have the option to select a computer base exam however please note computer base testing is only available in Toronto and Montreal (Canada). For international exams please select “No” and hit continue
If an exam session has already been arranged for the month and country you wish to write in follow these steps:
    Select the month you wish to write, country, province (if applicable) and city - hit continue
    Select the exam session by clicking in the circle under the “Status” hit continue
    Before continuing please ensure the information is correct and that you are familiar with the Exam Policies - if yes hit continue
    You will now be prompted for payment, please follow payment process
    You will have to confirm that you have read CSI’s Policies and Guidelines including Refund Policy and Privacy Policy – if yes select “I Agree” and then place your order
    Confirm the details of your booking to ensure they are correct. If yes select Done.
    You will receive an email confirmation of your exam booking, the same confirmation can be found in your message center. If you do not receive an email confirmation within 20 minutes of your exam booking please contact CSI.
    You can book only one exam per exam session.
If an exam session has not already been arranged for the month and county you wish to write in follow these steps:
    Select Book My Exam (you will see a list of the courses you are enrolled in).
    Select “Book a sitting in an alternate city” and hit continue.
    Select what country you wish to write your exam in.
    Select if you wish to write at a Regular International exam session or a Special International session (please refer to Exam Fees tab for costs).
    Input the Province/State (if applicable), City and Daytime Phone number – hit continue.
    Before continuing please ensure the information is correct and ensure you are familiar with the Exam Policies - if yes hit continue.
    You will now be prompted for payment, please follow payment process.
    You will have to confirm that you have read CSI’s Policies and Guidelines including Refund Policy and Privacy Policy – if yes select “I Agree” and then place your order.
    Confirm the details of your booking to ensure they are correct. If yes select Done.
    You will be contacted by CSI once your exam date, time and location have been confirmed.
    You can book only one exam per exam session.